Embattled salmon farmers are being urged to develop organic aquacrofts, or smallholdings, to rescue an industry reeling from plunging prices and a health scare that has tarnished the reputation of Scottish fish worldwide.

An aquaculture expert who, working with the Soil Association, set the standards for approving farmed fish as organic, told The Observer that the time had come for Scots to reclaim the industry from multinational corporations.

There was, claimed James Hepburn, little long-term economic or environmental sense in trying to compete with the massive Norwegian and Chilean factory farms that have flooded the global market with cheap fish.

He said it would be much wiser to plough a sustainable furrow of low-intensity farming along organic guidelines. Such a strategy required government backing and investment, but offered the prospect of Scottish fish once again becoming synonymous with quality and safety.

Hepburn formerly managed a large fish farm in the North-west of Scotland, but turned to the research and development of organic methods as he was worried about the procedures and chemicals used by mainstream operations.

'The industry needs to have vision right now,' said Hepburn. 'It will require some serious funding, but there is a real opportunity to move forward with confidence and develop a product that is sustainable and recognised globally as being different from the mass-produced fish turned out by the large corporations.'

His call comes as farmers of organically-produced salmon in Scotland reported a sales boom in the wake of a study which linked farmed fish to an increased risk of cancer.

Salmon producers said yesterday that the number of orders for organically produced salmon, which accounts for just 2 per cent of total domestic production, had risen by at least 10 per cent since an American report published in the respected journal Science earlier this month claimed that Scottish fish farms were among the most contaminated in the world.

At the Here organic shop in Chelsea Farmers Market in West London sales of salmon have climbed in the last week. 'We've been really busy,' said Here owner Troy Smith yesterday. 'People are worried about toxicity levels, growth hormones and chemicals used in large, commercial farms. They, rightly, have confidence in the products we sell.'

However, anti-salmon farm campaigners claim many of the problems facing mainstream farms also apply to organic ones. The American research team from the University of Albany in New York warned that eating more than three portions of Scottish salmon a year carried a cancer risk as levels of chemical contamination were higher than those in farmed and wild fish from other parts of the world.

Don Staniford of the Salmon Farm Protest Group pointed out last week that the dioxin and PCB pollution the scientists highlighted could also be found in organically farmed fish.

'The reason there are high levels of cancer-causing dioxins and PCBs is because the feed used in farms is heavily contaminated,' he said. Carnivorous fish such as salmon were reared in captivity using pellets made of creatures caught in the polluted North Sea. This was the case whether or not the farms followed organic guidelines, added Stanford, who also claimed that carnivorous aquaculture was inherently unsustainable because of the amount of feed required. Pellet production for farmers was emptying the oceans of many species of small fish.

James Hepburn accepts that even the organic sector has 'hurdles to clear', but sees it as the only hope for salmon farming. 'People want to eat this fish - there is a huge global market for it. Further investment in feeding methods is required so techniques can continue to evolve and improve.'

Hepburn's call for the industry to be gradually reshaped along organic lines, unsurprisingly finds favour with many small producers up and down Scotland's West Coast. When aquaculture arrived in the late 1970s and early 1980s it was seen as a salvation for small communities that had relied on crofting.

But soon large Norwegian and Dutch-owned corporations moved in to dominate the embryonic sector and the dream of establishing sustainable aquacrofts was largely lost. The current concern over mass production and plunging prices offers an opportunity to revive it.